Many automotive paints include flat flakes comprising metal and/or metal oxide as a paint pigment. These pigment flakes not only provide attractive visible properties to the automotive paint but also include the ability to reflect a high proportion of solar energy from the paint and the vehicle covered in the paint. At automotive plants where the paint is applied to automobile bodies, reciprocating pumps continuously circulate the paint to keep the pigment flakes and other ingredients in the paint from settling. Reciprocating pumps generally include several check valves. These check valves include a ball and a seat. In the past, both the ball and the seat were formed from stainless steel. While steel balls and steel seats in the check valves have proved satisfactory in many painting application environments, steel seats lack durability when the reciprocating pumps circulate paint containing these pigment flakes. These pigment flakes erode the stainless steel seats in the check valve as the paint circulates through the reciprocating pump, ultimately leading to failure of the check valves. This erosion problem has been addressed in the past by replacing the stainless steel seats with seats formed from tungsten carbide. The tungsten carbide seats are harder than the stainless steel seats and do resist erosion from the pigment flakes better than the stainless steel seats, however, the tungsten carbide seats are considerably more expensive than the stainless steel seats. Furthermore, the steel check ball can deform and lodge against the much harder tungsten carbide seat, resulting in failure of the check valve. Rubber O-rings have been combined with tungsten carbide and stainless steel seats to provide a softer contact between the ball and the seat. However, automotive paints can include a considerable amount of solvent which can prematurely degrade rubber O-rings.